External or Internal return pump?

[Bolivian Reefer]

I have a Rio 17HF rated to 660 gph for my 90 g. I want to upgrade it since it has been running for more than a year (with no problems). I dont want to wait until it fails (I travel a lot). I was thinking to get an internal Mag drive 9 or an external American Iwaki WMD-40RLT Pump (750 gph). I like the external since I will have less heat problems and in the long term, less AC consumption. Please let me know your thoughts. Thanks in advance for your recommendations

Javier

[alton]

I would go with a Panworld 50PX. If it is too much flow you can add a "T" with a valve to return the extra back to the sump.

[Fishbone]

For that size tank I would personally go with an internal eheim 1250 pump so long as your return line is a nice straight short shoot back up to the display. If you have complicated plumbing that pump will be under sized and you will need something bigger. Eheim are very reliable, sips energy. There is no great reason in my mind to put a ton of flow through the sump, less flow= less noise and energy. In my experience you just need enough flow through the return to keep the surface water of the display tank free of scam and build up.

[drunkfish3]

Iwakis' are great pumps and last forever but they do put heat in the tank so if that is you main reason for switching then i wouldn't choose it.

[Fishbone]

Iwaski are great pumps. I have some that have been in operation for over 10 years without a single issue

[Bolivian Reefer]

Any big difference from the american motor to the japanese one?

What flow do you recommend for a 90 gallon (120 soon) with an overflow box?

Thanks

[drunkfish3]

Only ever used the japanese ones and i have heard they are a lot better then the american.

[Fishbone]

Japanses bulk reef supply has a nice video comparing these on their website

[Bolivian Reefer]

Yes I just saw it and I will go for the Japanese. Now what I need help is what flow rate should I get for my 90g + sump? I have an overflow box and sometime soon in the future I will get rid of the overflow box and change it to a drilled system and maybe a 120 g.

Thanks

[Bolivian Reefer]

540, 750 or 960 gph?

[Fishbone]

An overflow box is a disaster waiting to happen. I would bit the bullet and drill the tank. If you don't plan your return around the specifications of the overflow box. The manufacturer should have a recommended flow rate. Use the RC calculator to see which pump is needed.

[Bolivian Reefer]

Yeah I am looking forward to change it and drill my tank. I will do it soon.

Would 540 gph @ 4' be enough flow for my 90g?

[Fishbone]

I would think that would be good but I would check the specifications of the overflow box. You don't want to much or to little flow with an overflow box. You can always put a ball valve on the return line to reduce flow some